Correspondence



93



as one can feel, there has been no injury to the wing. Therefore I should

be glad of any suggestion as to the cause of this curious feather.


E. Maud Knobel.



DIAGRAM OF THE DIVIDED FEATHER

(Reduced to half the natural size)



[For this drawing the two branches of the feather were forcibly pulled apart to

show their distinctness and structure. In the natural state they were closely

applied to one another in such a way that the planes of their upper surfaces were

at right angles. Miss Knobel informs us that the feather was the second primary

from the distal end. The interest of the record is one more piece of evidence of

the value Aviculture may be to Ornithology.— Eds.]



The Editors sent the feather to Mr. W. P. Pycraft, who kindly

favoured us with the following comments :—


“ Natural History Museum.


“ May 31, 1921.


“ The feather you sent is one of the most interesting of its kind

I have ever seen. I hope one or two others have been, or will be, saved.

I should like to have one. It is difficult to account for their curious

abnormality, but I suspect that it is due to the fusion of two feather

germs, owing to an abnormal shortening of that portion of the skeleton

to which this, or perhaps these two feathers, is attached. Will you ask

your correspondent which number in the series this represents ? If a

section were carefully and cleanly cut through the calamus of this feather,

I believe we should find a double column of pith cells, each representing

a single feather. But I have not ventured to cut the feather up.


“ If this explanation proves incorrect, then we must attribute it

to some abnormality or some injury to the papilla.”


SOUTH AFRICAN GROSBEAKS


Sirs,-— I have recently come into possession of three varieties of

South African Grosbeaks. These birds were privately imported, and

the people from whom I got them did not know their names, and I am

wondering whether any of our members can name them for me.



